1. Field of the Invention
This invention relates to artificial neurons and, more particularly, to pulse coupled optical neurons and a method for making optical pulse-coupled artificial neurons.
2. Prior Art
Although electronic computers are powerful tools for digital computation and information processing, their pattern recognition and image processing capabilities are far from satisfactory. Recently, many new computation architectures have been explored, including pulse-coupled neural networks: that is, a neural network that simulates the neural network found in biological systems. In such neural networks, the inputs to each neuron are weighted and summed. This sum is then compared with a threshold value. If the sum of the neural input signals exceeds the threshold value, a pulse signal will be produced by a pulse generator.
The essential element of most neural networks is the massive number of weighted interconnections used to combine relatively simple processing elements (neurons) together into a useful architecture. In prior art artificial neural network hardware architecture, interconnection among the neurons is realized using wires. The wiring is necessarily complicated when each neuron is connected to a large number of other neurons. The inherent parallelism and interconnection capability of optics make it an attractive means for the implementing the neural network interconnection process.
It is an object of the invention to provide an artificial neuron operable for receiving an optical input signal having an intensity and providing an optical output signal comprising a sequence of optical pulses having a pulse output frequency that depends on the intensity of the input signal, the artificial neuron comprising: (a) an input signal integrator operable for receiving and summing a plurality of optical input signals to provide an integrated electrical or optical input signal having an integrated signal intensity; and (b) an optical pulse generator operable for receiving said integrated electrical or optical input signal from said input signal integrator and provide optical output pulses having a frequency that is determined by said integrated signal intensity.
It is a further object of the invention to provide an optical neural network comprising a plurality of artificial neurons, each artificial neuron being operable for receiving an optical input signal having an intensity and providing an optical output signal comprising a sequence of optical pulses having a pulse output frequency that depends on said intensity, the artificial neuron further comprising: (a) an input signal integrator operable for receiving and summing a plurality of optical input signals to provide an integrated electrical or optical input signal having an integrated signal intensity; and (b) an optical pulse generator operable for receiving said integrated electrical or optical input signal from said input signal integrator and provide optical output pulses having a frequency that is determined by said integrated signal intensity.
It is still a further object of the invention to provide an artificial neuron adapted for optical communication with other artificial neurons and a method for making an artificial neuron.
It is yet a further object of the invention to provide an artificial neuron comprising an optoelectronic circuit, the artificial neuron comprising an optoelectronic circuit being adapted to be coupled with other similar artificial neurons by means of optical pulses.
It is another object of the invention to provide an artificial, all-optical neuron comprising a nonlinear Fabry-Perot etalon, the all-optical artificial neuron being adapted to be coupled with similar artificial neurons by means of optical pulses, and a method for making an all-optical artificial neuron.
It is another object of the invention to provide an artificial neuron network comprising an optically coupled array of artificial neurons adapted for applications in neural networks and/or image processing devices.
The features of the invention believed to be novel are set forth with particularity in the appended claims. However the invention itself, both as to organization and method of operation, together with further objects and advantages thereof may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which: